Field of the Invention
This invention relates to power transmission belts and, more particularly, to a belt installation jig that facilitates initial training of a belt around spaced pulleys for movement in an endless path.
Background Art
Japanese Unexamined Patent Publication No. 120678/2007 (Tokukai) discloses a belt installation jig that is used to direct a belt, capable of elastically stretching in a lengthwise direction, into a groove in a back-side pulley that is paired with a front-side pulley in a two-stage pulley system. The belt installation jig has an introduction part that engages the inside of the belt at a location axially spaced from a flange on the front-side pulley. A feeding guide part directs the belt to the pulley groove of the back-side pulley, spanning across the outer circumference of the front-side pulley between the introduction part and the guide part. A pressing piece prevents lifting of the belt. An attachment unit maintains the assembly, including the above components, on the two-stage pulley structure.
Belt installation jigs of the type shown in Tokukai are well known in the art. It is important in using these installation jigs that the installation jigs be stably maintained in a desired attitude during belt installation. Tokukai achieves this stability by coupling the introduction part, the feeding engagement part, and pressing piece to the two-stage pulley through the attachment unit. The integration of the operating components through the attachment unit is essential to Tokukai's operation.
One drawback with Tokukai's design is that the presence of the attachment unit increases the size of the overall belt installation jig. Given the space limitations in typical environments where the belts are used, those designing belt installation jigs strive to maintain the overall structure as compact as possible.
Further, the system is complicated by reason of having to connect the belt installation jig and two-stage pulley together in a manner that the belt installation jig will be maintained stably in a desired orientation during belt installation.